Injection molding is a process that involves injecting a moldable material, such as thermoformable resin, into a mold under pressure such that a resultant part has a shape conforming to a mold cavity of the mold. After the moldable material cools and solidifies, the part is removed from the mold.
Hydroforming is a process whereby a pressurized hydraulic fluid is applied to a ductile material such as some metals to shape the material. Hydroforming is typically used to shape tubing and other large structures. After the forming process is complete, the hydraulic fluid is removed from the shaped part. Combining aspects of injection molding and hydroforming techniques can improve manufacturing efficiency and cost of some product lines.